Gerry,
If you want to bend it back, the best way is to remove it and put it in a vise with some wood scraps supporting it. Depending how it is bent, you may be able to position the wood to where you can use the force of the vise to bend it back, or secure it and slip a box wrench over the end of it to use as a lever and go a little at a time.
Or, you can leave it on the bike and use a crowbar or a brick to pry/hammer it back into shape.
I prefer a little finesse myself...
